1. Field of the Invention
This invention relates generally to trailer hitch systems and their methods of use and in particular to a hitch system with neutral load indicator and shank guide and insertion stop.
2. Description of Related Art
The following art defines the present state of this field:
Wasservogel, U.S. Pat. No. 4,348,035 describes towing attachments for attaching trailers to the end of various vehicles including a tubular sleeve attached to the vehicle, an extension bar having one end rotatably attached to the tow bar of the trailer while the other end is adapted to be releasably attached to the tubular sleeve and having a cross-sectional shape which is complementary to that of the tubular sleeve so that it may slide smoothly into same for attachment thereto, and a clamp for releasably clamping the end of the extension bar to the tubular sleeve, the clamp including a fixed trunnion extending from the tubular sleeve and a resilient clamp affixed to the extension bar so that the resilient clamp can be releasably clamped to the fixed trunnion when the extension bar slides into the tubular sleeve, the resilient clamp being pivotable between a first position in which it does not interfere with the sliding of the extension bar into the tubular sleeve and a second position in which it prevents the extension bar from being slidably released from the tubular sleeve, and furthermore so that the tubular sleeve can be located inwardly with respect to the end of the vehicle to which the trailer is to be attached.
Vinchattle, U.S. Pat. No. 4,666,177 describes a hitch for coupling a drawbar on a draft vehicle to a tongue bar on a trailer or pulled vehicle including a preferably square tubular housing having a forward end for removable attachment to the drawbar and a rearward end for receiving and removably securing the tongue bar. Projecting from the rearward end is a four sided funnel or hopper shaped tongue bar guide comprising respective top and bottom immovable plates rigidly secured to the top and bottom edges of the housing and movable opposed side plates each hingedly secured to opposed sides of the housing so as to be separately movable away from and into abutment with the top and bottom plates. Spring means yieldingly hold the side plates in abutment with the top and bottom plates and a releasable locking assembly within the housing holds the side plates immovable while the tongue bar is being introduced and guided into the housing. A spring loaded hitch pin on the housing automatically engages the tongue bar at a predetermined point of movement with the tongue bar engaging the locking assembly to release it so that each side plate can yield and swing outwardly from contact by the tongue bar in a turning movement during travel. The side plates are automatically returned to locked position when the tongue bar is unhitched and removed from the housing.
LeVee, U.S. Pat. No. 4,669,748 describes a secured enclosure including a multi-compartmental enclosure, each compartment having a watertight door. The enclosure includes a powered vent system to provide circulation of air through the enclosure and a hitch receiving well formed in the enclosure for receiving a hitch for attaching a pulled vehicle to the pickup truck frame. The fifth wheel hitch of the invention includes engagement means for engaging a pulling vehicle, a mount for the engagement means, which is shiftable between an extended and retracted position, and an obstruction sensor which is operable to detect an impending impact between the pulling vehicle and the towed vehicle during the hitching process. Warning means are operable with the sensor to alert the operator of the impending impact.
Williams, Jr., U.S. Pat. No. 4,759,564 describes an automatic trailer hitch assembly mounting a shank unit on the trailer and a receiving unit on the towing vehicle. The shank unit provides an elongated shank member which mounts the trailer ball at one end coupled to a conventional trailer hitch ball socket housing secured to the trailer and at the opposite end is formed to slide on funnel-like guide passages into the receiving unit. A spring leveler assembly is detachably and adjustably secured as a subassembly to the trailing end of the shank unit, releasably grasps the ball socket housing and retains the shank unit properly positioned for coupling.
Rines, U.S. Pat. No. 5,454,482 describes an apparatus facilitating coupling of a trailer to a tow vehicle including a barrier against which a hitch ball may be positioned in the first stage of a hitching effort. The barrier includes clamps for barrier attachment to the trailer coupling. Support rods and a support plate on the barrier serve to position the barrier rearwardly adjacent the coupler socket. The barrier support plate may be inclined to abut a trailer frame having an inclined frontal surface. To position the trailer coupler laterally into place above a hitch ball, a lever is provided which utilizes the hitch ball as a fulcrum. An arm on the lever is engageable with the coupler to permit the application of force to move the trailer tongue and coupler into place above the hitch ball. Lowering of a trailer mounted jack results in downward engagement with the coupler onto the hitch ball. The barrier and lever are installed and removed without tools.
Draper, U.S. Pat. No. 5,927,742 describes an aligning apparatus which can be removably mounted to or built as an integral part of a towable trailer tongue for vertically aligning the inverted socket of the tongue with the mating ball which is conventionally mounted in cantilevered fashion on the rear end of the towing vehicle. The aligning apparatus includes a horizontally-lying V-shaped guide member having the open end of the V facing the drawbar in the operative position. The V-shaped guide member is positioned relative to the socket such that when the socket is at such a height so as to allow the socket to be positioned above the ball, the vertical center of the legs, the height of each leg constituting a camming surface, is at the height of the drawbar. This tongue height is achieved by use of a standard jack mechanism or pin-height adjustable vertical support pole on the trailer tongue. As the towing vehicle is backed up toward the trailer, if the ball is not aligned with the inverted socket, the drawbar will contact the camming surface of one leg of the V and shift the trailer tongue laterally to vertically align the socket with the ball. After alignment of socket with ball, the apparatus is either pivoted from the trailer tongue or removed to a stowed position so as to not interfere with the rear end of the towing vehicle during towing of the trailer around corners.
Hunter, U.S. Pat. No. 6,341,794 describes a trailer hitch alignment apparatus comprising a first guide member removably attached to a vehicle bumper and a second guide member removably attached to a trailer hitch socket. The first guide member includes a magnetic base with a telescopically extensible rod adjustably coupled thereto. The second guide member includes a magnetic base having an upwardly extending telescopic rod and a downwardly extending semi-flexible shaft attached thereto. The shaft extends downwardly through a bore defined by the trailer hitch tongue so as to contact the trailer hitch ball when the ball and socket are aligned. Contact between the shaft and ball causes vertical displacement of the shaft and guide rod. Therefore, the two telescopic guide rods, visible from a driver's seat, facilitates lateral alignment of the ball and socket while vertical displacement of the second rod indicates perfect forward alignment.
Grasso, et al., U.S. Pat. No. 6,517,098 describes an alignment device to align a vehicle's trailer hitch ball neck assembly with a trailer hitch socket assembly or tongue assembly. The present invention includes two units, each having uprights with engaging press on members. The ball neck upright member has a “C”-shaped bottom portion for frictionally engaging the neck of the trailer hitch ball neck, and the hitch engaging upright member has a “U”-shaped bottom portion for frictionally engaging the outer housing of the hitch socket member around its lower end periphery. When used in conjunction with each other, the two poles visually assist the vehicle operator in aligning the vehicles so that they may be easily coupled together for towing.
Our prior art search with abstracts described above teaches: a towing attachment for attaching trailers to vehicles, hitch construction, a fifth wheel hitch, an adjustable leveling device for automatic trailer hitching, an apparatus for hitching a trailer coupler to a hitch ball, and trailer hitch aligners, but does not teach a neutral weight alignment indicator with hitch pin hole alignment and hitch shank guide. The present invention fulfills these needs and provides further related advantages as described in the following summary.